Since there are a total of 15 shirts,
5 red shirts+4 white shirts= 9 shirts total
3 blue shirts+3 purple shirts= 6 shirts total
The odds that you would pick a red shirt and then a white are 3:2
3 being the 9 red and white shirts combined.
2 being the 6 purple and blue shirts combined.
9:6 simplified=3:2
9/3=3
6/3=2
3:2
Answer: The odds that you would pick a red shirt then a white shirt would be 3:2 or 60%